sorting - 对数字子字段的 GNU `sort(1)` 感到困惑

Question

我希望使用第二个字段中找到的数值对空格分隔的表进行排序。我可以假设第二个字段始终是 fooN 但 N 的长度未知:

antiq. foo11 girls
colleaguing foo2 Leinsdorf
Cousy foo0 Montgomeryville
bowlegged foo1 pollack
Chevrier foo10 ill-conceived
candlebomb foo3 seventieths
autochthony foo101 re-enable
beneficiate foo100 osteometric

我读了 man sort(1) 并尝试了各种选项。在我的系统上我发现了这一行:

sort -n -k2.5 table

上类。

我的问题是为什么？

根据手册页:

-k, --key=POS1[,POS2]
   start a key at POS1, end it at POS 2 (origin 1) 
...
POS is F[.C][OPTS], where F is the field number and C the characterposition in the
field. OPTS is one or more single-letter ordering options, which override global
ordering options for that key. If no key is given, use the entire line as the key. 

那么为什么 sort -n -k2.4 表不起作用而 sort -n -k2.5 却起作用？

Answer 1

我不知道这是否有帮助，但是info sort声明如下:

sort -t : -k 2,2n -k 5.3,5.4

 Note that if you had written `-k 2' instead of `-k 2,2' `sort'
 would have used all characters beginning in the second field and
 extending to the end of the line as the primary _numeric_ key.
 For the large majority of applications, treating keys spanning
 more than one field as numeric will not do what you expect.

也许尝试在 -k 和 2 之间添加空格，或者尝试设置 POS2？